The present invention generally relates to systems for pausing reproduction in rotary recording medium reproducing apparatuses, and more particularly to a system for pausing reproduction in a rotary recording medium reproducing apparatus, which advances the operational mode of the reproducing apparatus to a preset mode if reproduction is paused to temporarily discontinue reproduction in the midst of reproduction and the duration of the pause or pausing time is longer than a predetermined time period.
An information signal recording and reproducing system has been previously proposed and realized, in which the recording system forms pits in accordance with the information signal to record the information signal along a spiral track on a flat rotary recording medium (hereinafter simply referred to as a disc), without forming a groove therein. In the reproducing system, a reproducing stylus traces over along this track to reproduce the recorded information signal in response to variations in the electrostatic capacitance formed between a reproducing stylus and the disc.
In this previously proposed system, since no grooves are provided on the disc for guiding the reproducing stylus, it becomes necessary to record pilot or reference signals on or in the vicinity of a track of the information signal such as a video signal, on the disc. Upon reproduction, the reference signals are reproduced together with the video signal. Tracking control is carried out so that the reproducing stylus accurately traces along the track in response to the reproduced reference signals.
By use of this previously proposed system, there is no possibility whatsoever of the reproducing stylus or the disc being damaged, since the recording track has no groove. The reproducing stylus can trace the same portion of the track repeatedly many times, whereby a special reproduction such as still, slow-motion, or quick-motion picture reproduction becomes possible.
However, there are cases where it is necessary to temporarily discontinue reproduction when normal reproduction is being performed with respect to the disc, such as a case where the operator must answer a telephone call. That is, if the normal reproduction advances while the operator is having a telephone conversation in the above example, the operator will miss the picture reproduced during the telephone conversation. Moreover, the reproduced sound will interfere with the telephone conversation. Accordingly, in such a case, it is desirable to discontinue reproduction at the point when the operator answers the telephone call and resume reproduction from that point when the telephone conversation is finished.
In order to satisfy this demand, a system was proposed in which the reproducing apparatus can be put into a still picture reproduction mode by manipulating a pause button for temporarily discontinuing reproduction. By this manipulation of the pause button, a position on the reproducing track is maintained because the reproducing stylus scans over the same track. In this proposed system, the operational mode of the reproducing apparatus is returned to the normal reproduction mode from the still picture reproduction mode, by cancelling the manipulated pause button. However, in reality, the telephone conversation may be long, and the operator may forget to cancel the pausing state after the telephone conversation is finished.
In the above case where the pausing state is maintained for a long time period, the reproducing stylus will only scan and slide over the same track for this long time period. As a result, a groove will be formed on the flat recording surface of the disc due to friction, by the repetitive scanning of the same track.
Hence, in order to overcome the above deficiency, a system was tested in which the reproducing stylus is raised up to discontinue the contact between the disc during the above pause mode wherein the reproduction is discontinued. Because there is no contact between the disc and the reproducing stylus in this system even when the pausing time is long, a groove is prevented from being formed in the disc due to the repetitive scanning of the same track.
However, when an elevating mechanism for raising and lowering the reproducing stylus is used, the reproducing apparatus is inevitably affected by the mechanical error inherent to this elevating mechanism. For example, if the reproducing stylus is raised and then lowered, the lowered position is deviated by approximately 1 mm, for example, from the position before the reproducing stylus was raised. In this case, because the track pitch is 1.35 mm, deviation in the order of 740 tracks or 50 seconds in time (reproducing time of one track is 1/15 second) is introduced. Hence, after the pausing state is cancelled, reproduction will be resumed from a position 50 seconds before or after the position before the pause operation was effected. Thus, there is a disadvantage in that reproduced picture cannot be monitored in a continuous manner from the position before the pause operation was effected.